Method and apparatus for shaping bar stock by rolling

ABSTRACT

A PAIR OF SYNCHRONOUSLY ROTATING ROLLS IMPARTING ROTATION TO STOCK POSITIONED THEREBETWEEN, THE ROLLS BEING PROVIDED ON THEIR PERIPHERIES WITH CIRCUMFERENTIALLY EXTENDING WEDGE TOOLS HAVING SECTIONS FOR GROOVING, GUIDING, FORMING AND ULTIMATELY SEVERING THE STOCK. THE GUIDE SECTIONS OF THE TOOLS ARE AXIALLY OBLIQUE, SO THAT THE STOCK IS FED AXIALLY FROM THE GROOVING TO THE FORMING OPERATION AS A FUNCTION TO TOOL ROTATION AND THE USE OF A SEPARATE STOCK FEEDING MECHANISM IS NOT NECESSARY.

Oct. 12, 1971 v. HENCL 3,611,769

METHOD AND APPARATUS FOR SHAPING BAR STOCK BY ROLLING Filed May 6, 1969 2 Sheets-Sheet 1 M 2v x INVENTOR 0'63. .2 Wad/m f/enc/ V. HENCL Oct. 12, 1971 METHOD AND APPARATUS FOR SHAPING BAR STOCK BY ROLLING Filed May 6. 1969 2 Sheets-Sheet I INVENTOR Wad/n71? fienc/ BY W M g United States TPatent 01 fice Patented Oct. 12, 1971 3,611,769 METHOD AND APPARATUS FOR SHAPING BAR STOCK BY ROLLING Vladimir Hencl, Bilovice, Czechoslovakia, assignor to Vyzkumny ustav tvarecich stroju a technologie tvareni,

Brno, Czechoslovakia Filed May 6, 1969, Ser. No. 822,148 Int. Cl. B21h 9/00 US. Cl. 72-71 7 Claims ABSTRACT OF THE DISCLOSURE A pair of synchronously rotating rolls imparting rotation to stock positioned therebetween, the rolls being provided on their peripheries with circumferentially extending wedge tools having sections for grooving, guiding, forming and ultimately severing the stock. The guide sections of the tools are axially oblique, so that the stock is fed axially from the grooving to the forming operation as a function of tool rotation and the use of a separate stock feeding mechanism is not necessary.

SUMMARY OF THE INVENTION This invention relates to new and useful improvements in a method and apparatus for shaping bar stock, particularly cylindrical bar stock, by rolling the same between synchronously rotating rolls equipped with wedge tools, wherein the stock is shaped and parted during a single revolution of the rolls.

In accordance with conventional practice the stock is fed into the working space between the rolls by a separate feeding mechanism and rotation of the bar is stopped during the feeding operation, so that the bar must be set into rotation again for further rolling.

The principal object of the invention is to eliminate this disadvantage in a manner which avoids the use of a separate feeding mechanism and permits the stock shaping and parting operation to be carried out smoothly and expeditiously. This object is attained by utilizing rolling tools which are arranged on the rolls so that, in addition to shaping and/or parting the stock, they also serve to feed the same axially through the space between the rolls.

BRIEF DESCRIPTION OF DRAWINGS Other objects and features of the invention may become apparent from the following description taken in conjunction with the accompanying drawings, wherein like characters of reference are used to designate like parts, and wherein:

FIG. 1 is an elevational view of the tool-equipped rolls with the bar stock therebetween;

FIG. 2 is an end view thereof;

FIG. 3 is a fragmentary detail showing engagement of the stock by the wedge tools;

FIG. 4 is a view of one of the wedge tools in side elevation developed in a straight line;

FIG. 5 is a developed plan view of one of the rolls and tools thereon;

FIG. 6 shows an auxiliary wedge tool in a view similiar to that of FIG. 5; and

FIG. 7 is a developed side elevational view, in a straight line, of the wedge tool of FIG. 6.

DETAILED DESCRIPTION Referring now to the accompanying drawings in detail, FIG. 1 shows a pair of coacting rolls 1, 2 which are synchronously rotated by any suitable means in the same direction as indicated by the arrows S S respectively. The peripheries of the rolls are spaced apart to accommodate therebetween a cylindrical bar stock 4 which is engaged and rotated by the rolls 1, 2, as will be readily apparent.

Each of the rolls is provided on its periphery with a wedge tool 3, the same being elongated in the circumferential direction and having a shape which in a developed form is shown in FIGS. 4 and 5. Each wedge tool 3 has a starting point A disposed in a plane passing through the axes of the two rolls while an intermediate point B of the wedge tool is diametrically opposite, or spaced circumferentially by from the starting point A. The wedge tool includes several sections or portions of varying height as shown in the developed side elevation of FIG. 4. Thus, from the starting point A there is a section 3a which rises in the direction of roll rotation up to the point A This section 3a which may be referred to as the grooving section of the wedge tool may extend for approximately 30 of the rolls circumference.

The second 311 is followed by what may be referred to as the guide section 3b which is of a substantially uniform height up to the point B, whereupon follows a forming section 30. This increases in height from the point B up to a point B which may be spaced by approximately 15 from the point'B, and then the forming section 3c continues at substantially uniform height to the starting point A. In a circumferential continuation of the wedge tool 3, starting at the point A, is a parting tool 5.

Configuration of the wedge tool 3, developed in the axial plane, is shown in FIG. 5 from which it will be apparent that the grooving section 3a extends perpendlcularly to the roll axis from the starting point A to the point A whereupon there is an arcuate transition into the guide section 3b which extends axially obliquely to approximately the point B where another arcuate transition takes place to merge into the forming section 3c which then continues perpendicularly to the roll axis, or parallel to the section 3a, to the starting point A. It will be understood that the end of the section 3c at the point A is spaced axially from the start of the section 3a by the axial offset of the oblique guide section 312, which axial offset corresponds to the distance through which the stock 4 is to be fed. The parting tool 5 is spaced axially between the grooving section 3a and the axis 0 of the forming section 30, as shown in FIG. 5, by a distance determined by the length of the finished work piece which has its longitudinal center on the axis 0.

In operation, the bar stock 4 which may be heated in any suitable manner is inserted into the work space between the rolls 1, 2 up to a suitable stop (not shown) so that the starting point A of the grooving section 3a is at the longitudinal center of the future finished product. As the rolls are rotated and impart rotation to the stock, the section 3a forms a groove of a required depth in the stock, and as the guide section 3b enters the groove, the stock is fed axially to a position where the longitudinal center of the future finished product lies on the axis 0 of the forming section 30, the feeding of the stock being effected solely by the engagement of the oblique guide section 3b with the groove formed in the stock as aforesaid. Now the stock is shaped by the forming section 30 to its final configuration, which may or may not be spoolshaped as shown in the drawings, such final configuration being attained by the time the rolls 1, 2 have completed a single revolution.

At the beginning of the next revolution of the rolls the parting tool 5 comes into action and severs the finished workpiece from the stock, while the section 311 commences forming a groove in the stock for the next Workpiece, and thus the cycle of operation is repeated without interruption of the rotation of the bar for feeding.

During the stock forming operation of the forming section 30', the stock becomes slightly elongated in both directions. The spacing of the start of the grooving section 3a at the point A from the axis of the forming section 30 is determined by the required length of stock and the extent of its elongation during rolling, that is, the spacing is the sum of one-half the required stock length and one-half the finished workpiece length, and this spacing corresponds to the pitch or lead which is provided by the oblique guide section 311 in feeding the stock.

In a modified arrangement of the invention the grooving section 3a and the guide section 3b may be provided not as a unit with the forming section 3c, but as a separate auxiliary tool 6 shown in FIGS. 6 and 7 in a developed plan and a developed side elevational view, respectively. The tool 6 is arranged to start engaging the stock at the point where the future finished workpiece is severed, while the end of the tool 6 is preferably continuous with the parting tool 5. In an axially developed plane as shown in FIG. 6, the tool 6 has a portion between the points A and B which generally follows and is parallel to the tool sections 3a, 3b, while the portion of the tool between the points B and A is somewhat slanted away from the axis 0 of the section 30 to compensate for the aforementioned elongation of the workpiece during forming. Further still, the auxiliary tool 6 may be used together with the tool 3 so that the stock, after being formed by the tool 3 and ready to be engaged by the parting tool 5, is engaged at the center of the worlkpiece length 1 by the tool 6 and the two tools then feed the stock toward the axis 0 of the forming section 3c.

As already indicated, the invention does not require any separate mechanism for feeding the stock, since the feeding action is performed by the tools themselves without stopping the rotation of the bar. The drive of the stock by the rolls is thus more reliable, and the circumference of the rolls may be better used for the forming operation so that a more suitable geometry of the tools may be utilized. Also, when the tools 3 and 6 are used together, the stock is better guided, vibration is materially reduced, and more accurate rolling is possible.

I claim:

11. In a method of shaping cylindrical bar stock between a pair of synchronously rotating rolls comprising the steps of equipping said rolls with a wedge tool for working on said stock and at least one feed tool prior to said wedge tool, said feed tool being shaped to engage and advance said stock a predetermined distance between said rolls into position for working by said wedge tool and to dis- 4 engage from said stock on initiation of said working, continuously rotating the stock by rotation of the rolls, simultaneously feeding the stock axially to said rolls and effecting continuous cyclical advancement and wonking of said stock as a function of the tools so that a separate stock feeding mechanism is not necessary.

2. The method as defined in claim 1 which is further characterized in that the stock is engaged by the tools simultaneously at least at two points along its length.

3. The method as defined in claim 1 which is further characterized in that the stock is pre-rolled prior to advancement by the tools in the region of its subsequent shaping.

4. The method as defined in claim 3 which is further characterized in that the pre-rolling of the stock forms a groove therein which is engaged by the tools for axially feeding and working the stock.

5. In an apparatus for shaping cylindrical bar stock by rolling, the combination of a pair of synchronously rotating rolls adapted for receiving therebetween and imparting rotation to the stock, and wedge tools extending circumferentially on peripheries of said rolls, said tools including an initial stock grooving section, an intermediate guide section, an ultimate forming section, and a parting tool, said guide section extending axially obliquely of the roll axis whereby to feed the stock axially from the grooving to the forming position.

6. The apparatus as defined in claim 5 together with an auxiliary tool extending circumferentially on each of said rolls in axially spaced relation from said wedge tools, said auxiliary tool including grooving and guide portions for engaging the stock simultaneously with the grooving section and with the guide and forming sections of the wedge tools, respectively.

7. The method as defined in claim 1 wherein a portion of said stock is severed after wonkingand before advancement by said tools.

References Cited UNITED STATES PATENTS 672,664- 4/1901 Bornemann 727l 2,060,087 11/1936 Klamp 72-l00 LOWELL A. LARSON, Primary Examiner US. Cl. X.R. 72-98, 108 

